ABSTRACT
BACKGROUND: At present there are limited data about the effects of high frequency oscillatory ventilation (HFOV) in adult patients with acute respiratory distress syndrome (ARDS). This study evaluates efficacy of HFOV in such patients. METHODS: Sixteen ARDS patients, mean age 38.2 years (range 18-76), that underwent HFOV between 1997 and 2001 were enrolled in the study and evaluated in retrospect. FIo2, arterial blood gases, mean airway pressure (mean Paw), blood pressure, heart rate and central venous pressure were recorded by 4, 8, 12, 24, 48 and 72 h of HFOV and compared to conventional mechanical ventilation (CMV) at baseline (4 h prior to HFOV). RESULTS: On admission to the ICU, mean Simplified Acute Physiology score (SAPS II) was 40.3 (SD 12.6). Main causes of ARDS were pneumonia (9/16) and burn injuries (4/16). At baseline the patients had severe ARDS as noted by a mean lung injury score (LIS) of 3.2 (SD 0.3) and Pao2/FIo2 ratio 12.2 (SD 3.2) kPa. Within 4 h of HFOV, Pao2/FIo2 increased to 17.3 (SD 5.9) kPa (P = 0.016). Throughout HFOV, Pao2/FIo2 was significantly higher than at baseline. There were no significant changes in haemodynamic parameters. Ending HFOV after 6.6 (SD 3.2) days, survivors (n = 11) significantly reduced their Sequential Organ Failure Assessment Score (SOFA) compared to baseline. Survival at 3 months was 68.8%. CONCLUSION: HFOV effectively improves oxygenation without haemodynamic compromise. During HFOV, the SOFA score may predict outcome.
Subject(s)
High-Frequency Ventilation , Respiratory Distress Syndrome/therapy , APACHE , Adolescent , Adult , Aged , Burns/complications , Female , Hemodynamics , High-Frequency Ventilation/adverse effects , Humans , Male , Middle Aged , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/mortality , Respiratory Distress Syndrome/physiopathology , Respiratory Mechanics , Retrospective Studies , Survival RateABSTRACT
BACKGROUND: Methohexitone is widely used to provide anaesthesia for patients undergoing electroconvulstive therapy (ECT). Short seizure duration, high blood pressures (BP) and heart rates (HR) are usual in elderly patients. In this study, elderly patients undergoing ECT received low dose methohexitone with remifentanil or methohexitone alone and motor seizure duration, haemodynamic response and recovery time were compared. METHODS: Ten patients, of mean age 74.3 years, were enrolled in this double-blind, randomised crossover trial, receiving a total of 38 ECTs. Each patient was given the following two i.v. regimens in random order: A) methohexitone 0.5 mg kg(-1) combined with remifentanil 1.0 microg kg(-1) and B) methohexitone 0.75 mg kg(-1). Additional methohexitone was given, if needed, until loss of consciousness, and then suxamethonium 1.0 mg kg(-1) for muscular paralysis. RESULTS: Mean motor seizure duration was significantly longer with methohexitone-remifentanil (37.6 s (SD 12.0)) than with methohexitone alone (27.1 (SD11.5)) (P=0.0009). Recovery time, time to spontaneous breathing, peak postictal changes in BP and HR were similar with both regimens. CONCLUSION: A reduced dose of methohexitone combined with remifentanil allows prolonged duration of motor seizures in ECT. We conclude that low dose methohexitone combined with a short-acting opioid is a reasonable alternative for elderly patients undergoing ECT, and for other patients with short seizure duration.
Subject(s)
Anesthesia, Intravenous , Anesthetics, Intravenous , Electroconvulsive Therapy , Methohexital , Piperidines , Adult , Aged , Aged, 80 and over , Cross-Over Studies , Double-Blind Method , Female , Hemodynamics/drug effects , Humans , Male , Middle Aged , RemifentanilABSTRACT
Accurate measurement of optical radiation is required when sources of this radiation are used in biological research. The most difficult measurements of broadband noncoherent optical radiations usually must be performed by a highly trained specialist using sophisticated, complex, and expensive instruments. Presentation of the results of such measurement requires correct use of quantities and units with which many biological researchers are unfamiliar. The measurement process, physical quantities and units, measurement systems with instruments, and sources of error and uncertainties associated with optical radiation measurements are reviewed.
Subject(s)
Optics and Photonics/instrumentation , Radiation Monitoring/instrumentation , Radiation Monitoring/standards , Temperature , Time FactorsABSTRACT
Accurate measurement of optical radiation is required when sources of optical radiation are used in biological research. Such measurement of broad-band noncoherent optical radiations usually must be performed by a highly trained specialist using sophisticated, complex, and expensive instruments. Presentation of the results of such measurement requires correct use of quantities and units with which many biological researchers are unfamiliar. The measurement process, quantities, units, measurement systems and instruments, and uncertainties associated with optical radiation measurements are reviewed in this paper. A conventional technique for evaluating the potential hazards associated with broad-band sources of optical radiation and a spectroradiometer developed to measure spectral quantities is described. A new prototype ultraviolet radiation hazard monitor which has recently been developed is also presented. This new instrument utilizes a spectrograph and a spectral weighting mechanical mask and provides a direct reading of the effective irradiance for wavelengths less than 315 nm.
